Ultrahigh vacuum type scanning tunnelling microscopic (UHV-STM) and atomic force microscopic (AFM) measurements showed the existence of long periodical mound and valley shape (∼ 1 μm-period, ∼ 1.5 nm-height) at SiO 2 /Si(001) interface after removing native oxide. This shape was observed at the interface even after the formation of a thick (∼ 150 nm) thermal oxide or a chemical oxide made in HNO 3 solution. Fourier transform infrared spectroscopic (FTIR) measurements of the interfaces indicated the atomic scale roughness of the interface.
- Sacrificing oxidation
- Step structures